<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../reactBag/react.development.js"></script>
    <script src="../reactBag/react-dom.development.js"></script>
    <script src="../reactBag/babel.min.js"></script>
    <script src="../reactBag/prop-types.js"></script>
</head>
<body>
    <div id="app"></div>

    <script type="text/babel">

        class App extends React.Component{
            oIpt = React.createRef()
            render() {
                return <div>
                        <input type="text" ref = {this.oIpt}/>
                        <button onClick = {this.fn}>点一下</button>
                        <input type="text" onChange = {this.changeEle} placeholder = "修改表单打印输入的内容"/>
                        </div>
            }
            fn = () => {
                const {value} = this.oIpt.current;
                alert(value)
            }
            changeEle = (e) => {
                console.log(e.target.value);
            }
        }
        ReactDOM.createRoot(document.getElementById('app')).render(<App/>)
    </script>
</body>
</html>